DISSIPATING WAVES IN A HOT, COMPRESSIBLE, MAGNETIC, STRUCTURED ATMOSPHERE

The damping of ducted, fast, magnetohydrodynamic (MHD) waves by ion vi scosity and electron heat conduction in a radiating, optically thin, w arm, structured atmosphere has been evaluated. Dissipation is more eff ective in a warm plasma than in a 'cold' one but, for waves ducted by solar coronal loops, dissipation is only efficient if the periods of t he waves are shorter than a few tens of seconds and only if the backgr ound magnetic field is less than about 15 G. It appears that MHD waves of longer periods and in stronger magnetic fields will survive the di ssivative mechanisms considered here and may be manifest as observable coronal oscillations.